Characterized by a structural skeleton, curtain wall façades and tapered sides, it was among the first skyscrapers to abandon the customary block form.

The project was developed by architect Gio Ponti, with the assistance of Pier Luigi Nervi and Arturo Danusso.

Upon its completion in 1958, it became a symbol not only of Milan, but also of the economic recovery of Italy after the devastation of World War II.

On the afternoon of 18 April 2002, a Rockwell Commander 112 single-engine airplane registered in Switzerland hit the building.

Two goals of the restoration work were to maintain the structural and artistic integrity of the building and to upgrade its status as an executive headquarters by introducing new support services and technological systems.